Lynch Syndrome (LS) is an autosomal dominant inherited cancer syndrome that predisposes to colorectal, endometrial, gastric, ovarian, upper urinary tract, and other cancers
The presence of mismatch repair (MMR) deficiency helps identify patients at risk for Lynch syndrome (LS); however, it also occurs in ~15% of sporadic colorectal cancers
Differentiating colorectal tumors with MMR deficiency due to a sporadic somatic event from colorectal tumors with MMR deficiency due to a LS germline mutation is important
Universal screening of all colorectal cancer (CRC) specimens (NCCN, 2015; ASCO, 2014) and endometrial cancer specimens (ASCO, 2014; ESMO, 2013;NCCN, 2015) is recommended
Laboratory Testing
For additional information regarding testing strategies, refer to our Laboratory Test Directory
Additional Resources
ARUP’s Gastrointestinal Cancer Experts are nationally and internationally recognized pathologists, subspecialty-qualified clinicians, and board-certified clinical scientists.
ARUP Consult® is a laboratory test selection support tool with more than 2,000 lab tests categorized into topics and algorithms. ARUP Consult Colorectal Cancer

- ARUP Consult
Lynch Syndrome - Hereditary Nonpolyposis Colorectal Cancer (HNPCC) - Samowitz WS, Evaluation of colorectal cancers for Lynch syndrome: practical molecular diagnostics for surgical pathologists.
Modern Pathology (2015) 28, S109–S113 - Molecular Testing in GI Cancer
Video Lecture